docs: def is_valid_combination(values, names):
  
      dictionary = dict(zip(names, values))
  
      """
      Should return True if combination is valid and False otherwise.
  
      Dictionary that is passed here can be incomplete.
      To prevent search for unnecessary items filtering function
      is executed with found subset of data to validate it.
      """
  
      rules = [
          # Brand Y does not support Windows 98
          # Brand X does not work with XP
          # Contractors are billed in 30 min increments
          lambda d: "98" == d["os"] and "Brand Y" == d["brand"],
          lambda d: "XP" == d["os"] and "Brand X" == d["brand"],
          lambda d: "Contr." == d["employee"] and d["increment"] < 30,
      ]
  
      for rule in rules:
          try:
              if rule(dictionary):
                  return False
          except KeyError:
              pass
  
      return True